1. Field of the Invention
This invention relates to detection of leaks in heat exchangers, and more specifically to visible detection of a leak from one heat exchanger side to the other heat exchanger side using gas pressure build-up to create bubbles in a liquid outside the heat exchanger.
2. Prior Art
Heat exchangers comprise a first side, sometimes referred to as a product side, and a second side, sometimes referred to as a media side, in close contact with the first side. Plate heat exchangers that comprise a number of plates closely packed in series with fluids flowing through them while maintaining the two sides separate. Plate heat exchangers are commonly used in food processing where it is imperative that the fluids from the two sides remain separate, that is, that there are no leaks between the two heat exchanger sides that could cause cross contamination. Cross contamination occurs when a crack or pinhole develops, allowing fluids on one side to pass from one side into the other side and mix with fluids on that side usually assisted by a pressure difference that exists between the two sides. Because contamination can have serious consequences, it is routine to check the plates for any defect that may result in a leak.
Checking for defects usually involves removing a plate and testing it apart from the heat exchanger. Disassembly of the heat exchanger is time consuming and interrupts its use. The need remains for a device and method that can perform a quick and easy test on a heat exchanger in place without removal and disassembly of the heat exchanger to minimize interruption of use of the heat exchanger.